stm32mp1: ram: change ddr speed to kHz

Allow fractional support in DDR tools.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/doc/device-tree-bindings/memory-controllers/st,stm32mp1-ddr.txt b/doc/device-tree-bindings/memory-controllers/st,stm32mp1-ddr.txt
index 3028636..e5b1bb5 100644
--- a/doc/device-tree-bindings/memory-controllers/st,stm32mp1-ddr.txt
+++ b/doc/device-tree-bindings/memory-controllers/st,stm32mp1-ddr.txt
@@ -16,7 +16,7 @@
 info attributes:
 ----------------
 - st,mem-name	: name for DDR configuration, simple string for information
-- st,mem-speed	: DDR expected speed for the setting in MHz
+- st,mem-speed	: DDR expected speed for the setting in kHz
 - st,mem-size	: DDR mem size in byte
 
 
@@ -173,7 +173,7 @@
 				      "ddrphycapb";
 
 			st,mem-name = "DDR3 2x4Gb 533MHz";
-			st,mem-speed = <533>;
+			st,mem-speed = <533000>;
 			st,mem-size = <0x40000000>;
 
 			st,ctl-reg = <